Algal Bloom raises concern

MOSSEL BAY NEWS - For the past two weeks, a very visible algal bloom, wrongly known as "red tide", has been visible in the sea off Mossel Bay.

According to Stephen Lamberth, a scientist at the Department of Agriculture, Forests and Fisheries, all algal blooms should be treated as potentially toxic and no mussels or oysters should be harvested and eaten.

This is a totally natural event that occurs when certain algae known as dinoflagellates, explode, creating an algal bloom. It is when the millions of microscopic algae re-produce and cluster in one area, that the water changes colour into a rusty red.

The main reasons for an algal bloom, is a high content of nutrients and a warmer than usual sea temperature. Last week, the water measured 20 degrees celsius. Sometimes these blooms also produce nocturnal bioluminescence that lights up with wave action. Reports of this beautiful event were received last week. Professor Rudy van der Elst had the following comment when contacted on Tuesday: "Calm conditions, temperature and nutrients are features that contribute to blooms of plankton and jellyfish.

"However, the science is far from perfect and more study is needed to understand these processes, including a possible implication of climate change. The University of the Western Cape has some scientists working on these issues."

Water samples have been taken and sent to the Department of Agriculture, Forestry and Fisheries (DAFF) in order to establish exactly what algae is present in Mossel Bay.

The dusty red colour of the algal bloom currently occurring in Mossel Bay, can clearly be seen.